Bridge type detonators are commonly used for initiating or firing an explosive such as the various stages of a rocket. Electrical characteristics necessary for such use are a fast function time, repeatability or simultaneity with respect to firing time, cost effectiveness and most importantly, safety. With regard to safety, a standard no fire test for such initiators of the above type is the application of one ampere or one watt to the initiator to insure that no malfunction will occur.
In general operation for a detonator of a the thin film bridge type, a primer such as lead styphnate is placed on the bridge and when sufficient current is passed through the bridge its inherent resistance heating will fire or detonate the primer. Normally the thin film bridge is part of an explosive cap shell which has a pair of leads extending from it to which the electrical firing impulse is provided.